U.S. patent number 8,857,330 [Application Number 13/995,229] was granted by the patent office on 2014-10-14 for screen printer and screen printing method.
This patent grant is currently assigned to Panasonic Corporation. The grantee listed for this patent is Isao Horie, Hideki Uchida, Takashi Yazawa. Invention is credited to Isao Horie, Hideki Uchida, Takashi Yazawa.
United States Patent |
8,857,330 |
Uchida , et al. |
October 14, 2014 |
Screen printer and screen printing method
Abstract
A holding mechanism 40 is made up of a shaft support 44 that is
provided while joined to a joint and that has a vertically-oriented
pivot 44a, a shaft member 45 that horizontally extends from the
shaft support 44 and that is turnable around the pivot 44a, and a
fitting section 36 that is formed in a squeegee unit 16 and to
which the shaft member 45 is removably fitted. Thereby, the
entirety of the squeegee unit 16 becomes removably attachable by
only moving the squeegee unit 16 in a horizontal direction.
Inventors: |
Uchida; Hideki (Yamanashi,
JP), Horie; Isao (Yamanashi, JP), Yazawa;
Takashi (Yamanashi, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Uchida; Hideki
Horie; Isao
Yazawa; Takashi |
Yamanashi
Yamanashi
Yamanashi |
N/A
N/A
N/A |
JP
JP
JP |
|
|
Assignee: |
Panasonic Corporation (Osaka,
JP)
|
Family
ID: |
48288974 |
Appl.
No.: |
13/995,229 |
Filed: |
September 11, 2012 |
PCT
Filed: |
September 11, 2012 |
PCT No.: |
PCT/JP2012/005765 |
371(c)(1),(2),(4) Date: |
June 18, 2013 |
PCT
Pub. No.: |
WO2013/069183 |
PCT
Pub. Date: |
May 16, 2013 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20130269552 A1 |
Oct 17, 2013 |
|
Foreign Application Priority Data
|
|
|
|
|
Nov 9, 2011 [JP] |
|
|
2011-245145 |
|
Current U.S.
Class: |
101/129; 101/123;
427/282; 118/406 |
Current CPC
Class: |
H05K
3/1233 (20130101); B41F 15/42 (20130101); B41F
15/44 (20130101); H05K 3/3485 (20200801) |
Current International
Class: |
B41M
1/12 (20060101); B41F 15/40 (20060101); B41F
15/08 (20060101) |
Field of
Search: |
;101/114,123,124,126,129,366 ;118/213,301,406,667,712 ;427/282 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
04-284249 |
|
Oct 1992 |
|
JP |
|
2002-172756 |
|
Dec 2000 |
|
JP |
|
2002-225222 |
|
Feb 2001 |
|
JP |
|
2002-001905 |
|
Jan 2002 |
|
JP |
|
2003-505273 |
|
Feb 2003 |
|
JP |
|
2004-25694 |
|
Jan 2004 |
|
JP |
|
2004-130516 |
|
Apr 2004 |
|
JP |
|
Other References
International Search Report for PCT/JP2012/005765 dated Oct. 16,
2012. cited by applicant.
|
Primary Examiner: Evanisko; Leslie J
Assistant Examiner: Ferguson Samreth; Marissa
Attorney, Agent or Firm: Pearne & Gordon LLP
Claims
The invention claimed is:
1. A screen printer that prints a substrate with paste by a pattern
hole of a mask plate, the screen printer comprising: a squeegee
head configured to slide over the mask plate via a head drive
mechanism, the squeegee head comprises a joint joined to the head
drive mechanism; a replaceable paste reservoir that stores paste; a
paste pressurizing unit that is placed on the joint and that
pressurizes the paste in the paste reservoir; a print space that
stores the pressurized paste and that brings the paste into contact
with a surface of the mask plate; and two scraping members that
form front and back walls of the print space in a squeegeeing
direction and whose lower ends contact a surface of the mask plate;
the paste reservoir, the print space, and the scraping members
configure a squeegee unit that can be integrally attached to and
detached from the joint; and a holding mechanism that positions and
holds the squeegee unit with respect to the joint having a shaft
support which is joined to the joint and which has a
vertically-oriented pivot, a shaft member that horizontally extends
from the shaft support and that is turnable around the pivot, and a
fitting section that is formed in the squeegee unit and to which
the shaft member is removably fitted.
2. The screen printer according to claim 1, wherein the holding
mechanism has a turn inhibition mechanism that inhibits relative
turning between the fitting section and the shaft member while the
shaft member is fitted into the fitting section.
3. The screen printer according to claim 1, wherein the holding
mechanism has a positional misalignment prevention mechanism that
regulates occurrence of axial, radial, relative displacement
between the fitting section and the shaft member while the shaft
member is fitted to the fitting section.
4. The screen printer according to claim 1, wherein an upper
portion including the paste reservoir is separable from a lower
portion including the print space within the squeegee unit; the
upper portion and the lower portion are hinged together; and the
upper portion can be opened and closed while axially supported by
the lower portion.
5. A screen printing method for printing a substrate with paste
through a pattern hole of a mask plate, the method comprising the
steps of: providing a squeegee head configured to slide over the
mask plate via a head drive mechanism, the squeegee head comprises:
a joint joined to the head drive mechanism; a replaceable paste
reservoir that stores paste; a paste pressurizing unit that is
placed on the joint and that pressurizes the paste in the paste
reservoir; a print space that stores the pressurized paste and that
brings the paste into contact with a surface of the mask plate; two
scraping members that form front and back walls of the print space
in a squeegeeing direction and whose lower ends contact a surface
of the mask plate; the paste reservoir, the print space, and the
scraping members configure a squeegee unit that can be integrally
attached to and detached from the joint; and a holding mechanism
that positions and holds the squeegee unit with respect to the
joint having a shaft support which is joined to the joint and which
has a vertically-oriented pivot, a shaft member that horizontally
extends from the shaft support and that is turnable around the
pivot, and a fitting section that is formed in the squeegee unit
and to which the shaft member is removably fitted; pressurizing the
paste in the paste reservoir to house the paste in the print space
below and bring the paste into contact with the surface of the mask
plate; and sliding the squeegee head over the mask plate by the
head drive mechanism to thereby print the paste, wherein when the
paste in the paste reservoir has run out the squeegee unit is
rotated with respect to the joint by turning the shaft member
around the shaft support, and the fitting section is detached from
the shaft member, thereby separating the squeegee unit from the
joint and replacing the paste reservoir.
Description
TECHNICAL FIELD
The invention relates to a screen printer and a screen printing
method for printing a substrate with paste, like cream solder and
conductive paste.
BACKGROUND ART
A method using a closed squeegee head has hitherto been known as a
screen printing method of printing a substrate with paste, like
cream solder and conductive paste, in an electronic component
mounting step. Under the method, as opposed to normal screen
printing in which paste is fed directly over a mask plate, paste in
a squeegee head is pressurized while the squeegee head with
internally stored paste is held in contact with a mask plate.
The paste is thereby squeezed into pattern holes of the mask plate
by a paste contact surface provided on a lower surface of the
squeegee head. The squeegee head is then slid over the mask plate,
thereby sequentially filling the respective pattern holes with the
paste (see; for instance, Patent Document 1). In the example
described in connection with the patent document, the squeegee head
is separated into an upper portion including a cartridge that
stores the paste and a lower portion including a printing space
where the pressurized paste is brought into contact with the mask
plate. The upper portion is reclosable while axially fastened to
the lower portion.
RELATED ART DOCUMENT
Patent Document
Patent Document 1: JP-A-2002-1905
DISCLOSURE OF THE INVENTION
Problem that the Invention is to Solve
The related art technique described in connection with the patent
document, however, has a drawback, such as that described below.
Specifically, in the related art technique, the squeegee head is
separated into the upper portion and the lower portion. The
cartridge is replaced by opening the upper portion. For this
reason, a space where the upper portion is turned while the
squeegee head remains attached to the printer is required, which
results in an impediment to miniaturization of a configuration of
the squeegee head in the printer. Cartridge replacement must be
performed in a narrow space at paste replenishment work while the
squeegee head is kept attached to the printer. Therefore,
workability is poor, and time and efforts are consumed every time a
cartridge is replaced.
Accordingly, the invention aims at providing a screen printer and a
screen printing method that enable miniaturization of a
configuration of the printer and easy performance of cartridge
replacement work.
Means for Solving the Problem
A screen printer of the invention is directed toward a screen
printer that prints a substrate with paste by pattern holes of a
mask plate by sliding a squeegee head over the mask plate with a
head drive mechanism, wherein the squeegee head has a joint joined
to the head drive mechanism, a replaceable paste reservoir that
stores paste, paste pressurizing unit that is placed on the joint
and that pressurizes the paste in the paste reservoir, a print
space that stores the pressurized paste and that brings the paste
into contact with a surface of the mask plate, and two scraping
members that form front and back walls of the print space in a
squeegeeing direction and whose lower ends contact a surface of the
mask plate; the paste reservoir, the print space, and the scraping
members configure a squeegee unit that can be integrally attached
to and detached from the joint; and a holding mechanism that
positions and holds the squeegee unit with respect to the joint has
a shaft support which is joined to the joint and which has a
vertically-oriented pivot, a shaft member that horizontally extends
from the shaft support and that is turnable around the pivot, and a
fitting section that is formed in the squeegee unit and to which
the shaft member is removably fitted.
A screen printing method of the invention is directed toward a
screen printing method for printing a substrate with paste through
pattern holes of a mask plate by sliding a squeegee head over the
mask plate by a head drive mechanism, wherein the squeegee head has
a joint joined to the head drive mechanism, a replaceable paste
reservoir that stores paste, paste pressurizing unit that is placed
on the joint and that pressurizes the paste in the paste reservoir,
a print space that stores the pressurized paste and that brings the
paste into contact with a surface of the mask plate, and two
scraping members that form front and back walls of the print space
in a squeegeeing direction and whose lower ends contact a surface
of the mask plate; the paste reservoir, the print space, and the
scraping members configure a squeegee unit that can be integrally
attached to and detached from the joint; a holding mechanism that
positions and holds the squeegee unit with respect to the joint has
a shaft support which is joined to the joint and which has a
vertically-oriented pivot, a shaft member that horizontally extends
from the shaft support and that is turnable around the pivot, and a
fitting section that is formed in the squeegee unit and to which
the shaft member is removably fitted: when the paste in the paste
reservoir has run out in processes of pressurizing the paste in the
paste reservoir in the squeegee head, to thus house the paste in
the print space located below and bring the paste into contact with
the surface of the mask plate, thereby printing the paste, the
squeegee unit is rotated with respect to the joint by turning the
shaft member around the shaft support, and the fitting section is
detached from the shaft member, thereby separating the squeegee
unit from the joint and replacing the paste reservoir.
Advantage of the Invention
According to the invention, the squeegee unit is made up of the
paste reservoir, the print space, and the scraping members and
removably attached to or detached from the joint in an integrated
fashion. The holding mechanism that positions and holds the
squeegee unit with respect to the joint is made up of: the shaft
support that is joined to the joint and that has the
vertically-oriented pivot; the shaft member that horizontally
extends from the shaft support and that is turnable around the
pivot; and the fitting section that is formed in the squeegee unit
and to which the shaft member is removably fitted. As a result, the
entirety of the squeegee unit can be made removably attachable by
only moving the squeegee unit in the horizontal direction.
Miniaturization of the screen printer and facilitation of cartridge
replacement work can be implemented.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a screen printer of an embodiment of the
invention.
FIG. 2 is a side view of the screen printer of the embodiment of
the invention.
FIG. 3 is a perspective view of a squeegee head of the screen
printer of the embodiment of the invention.
FIG. 4 is a fragmentary sectional view of the squeegee head of the
screen printer of the embodiment of the invention.
FIG. 5 is descriptive views in which (a) and (b) show configuration
of a squeegee unit of the screen printer of the embodiment of the
invention.
FIG. 6 is a descriptive view in which (a), (b), and (c) show
configuration of the squeegee unit and an open-close mechanism of
the screen printer of the embodiment of the invention.
FIG. 7 is a descriptive view showing an open-close state of the
squeegee unit of the screen printer of the embodiment of the
invention.
FIG. 8 is a descriptive view in which (a) to (e) show configuration
of a joint in the squeegee head of the screen printer of the
embodiment of the invention.
FIG. 9 is a descriptive view in which (a) and (b) show operation
pertaining to a method for removal attachment of the squeegee unit
in the screen printer of the embodiment of the invention.
FIG. 10 is a descriptive view in which (a) and (b) shows operation
pertaining to a method for removal attachment of the squeegee unit
in the screen printer of the embodiment of the invention.
EMBODIMENT FOR IMPLEMENTING THE INVENTION
An embodiment of the invention is now described by reference to the
drawings. An entire configuration of a screen printer 1 is first
described by reference to FIGS. 1, 2, and 3. The screen printer 1
exhibits the following function. Namely, a squeegee head 10 is slid
over a mask plate 7 by a head drive mechanism 13, thereby printing
a substrate 5 with cream solder 9, which is electronic component
bonding paste, by pattern holes 7a of the mask plate 7. In FIGS. 1
and 2, the screen printer 1 is configured such that the mask plate
7 held by a mask holder 8 is disposed at an elevated position above
a substrate positioning section 2 and that a screen printing
mechanism is also placed above the mask plate 7.
A configuration of the substrate positioning section 2 is
described. A substrate underpart receiver 4 is disposed on an upper
surface of a moving table 3 so as to be capable of ascending and
descending actions. The substrate 5 which is a target of printing
is held from its underside by elevation of the substrate underpart
receiver 4. In addition, the substrate 5 is sandwiched and fixed
sidewise between a pair of clamp members 6. By actuation of the
moving table 3, the substrate 5 is positioned in a horizontal
direction with respect to the mask plate 7, coming into contact
with an underside of the mask plate 7 fixed by the mask holder
8.
A configuration of the screen printing mechanism is now
described.
The squeegee head 10 placed above the mask plate 7 is actuated by
the head drive mechanism 13 made up of a head elevation mechanism
11 and a head moving mechanism 12. The head elevation mechanism 11
is placed on a horizontal moving plate 11b, and a joint block 14b
of a joint 14 that makes up the squeegee head 10 is joined to an
elevation shaft 11a that extends downwards from the head elevation
mechanism 11. The squeegee head 10 moves up and down with respect
to the mask plate 7 by actuation of the head elevation mechanism
11, whereupon scraping members 18A and 18B attached to an underside
of the squeegee head 10 come into contact with an upper surface of
the mask plate 7.
A configuration of the head moving mechanism 12 is described. A nut
12c is joined to the underside of the moving plate fib. A feed
screw 12b screw-engaged with the nut 12c is rotationally driven by
a motor 12a. As shown in FIG. 2, a slider 20 is fixed to either end
on the underside of the moving plate 11b, and the sliders 20 are
slidably fit on guide rails 22 laid on upper surfaces of respective
frames 21. The moving plate 11b is horizontally moved by driving
the motor 12a, whereupon the squeegee head 10 joined to the
elevation shaft ha also moves in a horizontal direction. The motor
12a is driven while the squeegee head 10 is held lowered, the
squeegee head 10 horizontally moves over the mask plate 7.
Specifically, the motor 12a, the feed screw 12b, and the nut 12c
configure the head moving mechanism 12 that horizontally moves the
squeegee head 10 over the mask plate 7.
A configuration of the squeegee head 10 is now described. As shown
in FIGS. 3 and 4, the squeegee head 10 is equipped with a squeegee
unit 16 that fills the pattern holes 7a with cream solder 9, which
is paste, on contact with a surface of the mask plate 7. The
squeegee unit 16 is split into an upper portion 16A and a lower
portion 16B. In the embodiment, the squeegee unit 16 into which the
upper portion 16A and the lower portion 16B are integrated is
joined to the moving plate 11b of the head drive mechanism 13 with
the joint 14. The squeegee unit 16 is positioned and held with
respect to the joint 14 by a holding mechanism 40, which will be
described later.
As shown in FIG. 3, the upper portion 16A and the lower portion 16B
are equipped with an body upper portion 30A and a body lower
portion 30B that are block-shaped members and elongated in a
widthwise direction of the mask plate 7. As shown in FIG. 2, the
length of the body upper portion 30A and the length of the body
lower portion 30B are set so as to cover a width of the substrate 5
that is a target of printing. The body upper portion 30A and the
body lower portion 30B are reclosably joined together with a hinge
17.
An indentation 30a to which a cartridge 31 storing the cream solder
9 is removably attached is formed in the body upper portion 30A.
The cartridge 31 serves as a paste reservoir where a predetermined
amount of the cream solder 9 is stored and is attached to the body
upper portion 30A during printing. A pressurizing plate 32 that
pressurizes the cream solder 9 stored in the cartridge is fitted
into an opening formed in an upper surface of the cartridge 31. A
depressing member 15b joined to a rod 15a of a cylinder 15 mounted
on a joint plate 14a remains in contact with an upper surface of
the pressurizing plate 32. The pressurizing plate 32 can be pressed
down within the cartridge 31 by actuation of the cylinder 15.
A bottom side of the cartridge 31 serves as a cream solder
extruding plate 31a, and a plurality of openings 31b are formed in
the extruding plate 31a. The pressurizing plate 32 is pressurized
downward with the cylinder 15, whereupon the cream solder 9 in the
cartridge 31 is pressurized and extruded downward by the openings
31b of the extruding plate 31a. The cylinder 15 serves as paste
pressurizing unit that is placed on the joint plate 14a to
pressurize the cream solder 9, which is paste, within the cartridge
31.
An overall opening 30b that is in mutual communication with an
interior of the cartridge 31 is provided in the body lower portion
30B. An adhesion inhibition plate 33 is disposed on the overall
opening 30b while remaining in contact with the extruding plate 31a
on the bottom of the cartridge 31. Circular openings 33a are
formed, while aligned to the corresponding openings 31b of the
extruding plate 31a, in the adhesion inhibition plate 33 (see also
FIG. 7). The adhesion inhibition plate 33 inhibits the cream solder
9, which is extruded downward from the cartridge 31, from adhering
to the bottom of the cartridge 31; namely, an area of the underside
of the extruding plate 31a other than the openings 31b.
A squeezing plate 34 with a plurality of openings 34a in the same
way as does the extruding plate 31a of the cartridge 31 is provided
on the bottom of the overall opening 30b of the body lower portion
30B. When extruded under pressure of the cylinder 15, the cream
solder 9 passes downwards through three stages; namely, the
openings 31b of the extruding plate 31a, the openings 33a of the
adhesion inhibition plate 33, and the openings 34a of the squeezing
plate 34. The thus-extruded cream solder 9 arrives at a space
formed beneath the body lower portion 30B; namely, a print space 35
enclosed by the underside of the body lower portion 30B and the two
scraping members 18A, 18B placed on an underside of the body lower
portion 30B at inward inclines.
The scraping members 18A, 18B form front and back walls of the
print space 35 in a squeezing direction. In a state where the
squeegee head 10 is lowered, lower ends of the respective scraping
members 18A and 18B contact the surface of the mask plate 7. During
printing operation, the print space 35 stores the pressurized cream
solder 9 and brings the cream solder 9 into contact with the
surface of the mask plate 7 by a print plane existing between the
scraping members 18A and 18B.
The cream solder 9 in the cartridge 31 is pressurized by lowering
the pressurizing plate 32, thereby migrating to an interior of the
print space 35 while passing through the extruding plate 31a, the
adhesion inhibition plate 33, and the squeezing plate 34. A
sectional area of a migration pathway of the cream solder 9 is
narrowed in midstream by the plurality of small openings 31b, 33a,
and 34a. As a result of the pressurized cream solder 9 passing
through the openings, a viscosity of the cream solder 9 decreases,
whereby the cream solder 9 is reformed to a property suitable for
screen printing.
Specifically, the squeegee head 10 described in connection with the
embodiment includes the joint 14 joined to the head drive mechanism
13, the cartridge 31 that serves as the replaceable paste reservoir
for storing the cream solder 9; the head elevation mechanism 11
that is placed on the joint 14 and that pressurizes the cream
solder 9 in the cartridge 31; the print space 35 that stores the
thus-pressurized cream solder 9 and that brings the cream solder 9
into contact with the surface of the mask plate 7; and the two
scraping members 18A, 18B that configure front and back walls of
the print space 35 in the squeezing direction and whose lower ends
contact the surface of the mask plate 7. The squeegee unit 16 that
can be integrally attached to and detached from the joint 14 is
made up of the upper portion 16A that houses the cartridge 31 and
the lower portion 16B that has the print space 35 and the scraping
members 18A and 188.
By reference to (a) and (b) in FIG. 5, (a), (b), and c in FIG. 6,
and FIG. 7, the configuration of the squeegee unit 16 and
coupling/decoupling and opening-closing operation of the upper
portion 16A and the lower portion 16B that configure the squeegee
unit 16 are now described. As shown (a) in FIG. 5, the hinge 17 for
hinging together the upper portion 16A and the lower portion 16B is
provided on one side surface of the squeegee unit 16.
Provided on the other side surface of the squeegee unit 16 is a
fitting section 36 that makes up the holding mechanism 40 for
integrally holding the squeegee unit 16 on the joint 14. The
fitting section 36 is provided on partial, lateral protuberances
from the body lower portion 30B of the lower portion 16B. The
fitting section 36 is made up of a hole 37 having a fitting slot
37a intended for fit insertion of a shaft member 45 (FIG. 8) and a
positioning section 38 on which a positioning pin 38a to fit into a
positioning hole 41a (FIG. 8) is projectingly provided.
As mentioned above, the squeegee unit 16 is split into the upper
portion 16A including the cartridge 31 and the lower portion 16B
including the print space 35. The upper portion 16A and the lower
portion 16B are separably, reclosably hinged together by the hinge
17. As shown in (a) in FIG. 6, a hinge plate 17a with a pin 17b is
fixed to a side surface of the upper portion 16A, and a hinge plate
17c with a pin groove 17d is fixed to a side surface of the lower
portion 16B. The hinge plate 17c is partially cut out, and an upper
portion of the pin groove 17d is partially opened. When the upper
portion 16A is attached onto the lower portion 16B, the pin 17b is
fitted, as shown in (b) in FIG. 6, into the pin groove 17d by the
cutout of the hinge plate 17c. The upper portion 16A is thereby
attached to a correct position on an upper surface of the lower
portion 16B.
The upper portion 16A in this state is turned around the pin 17b as
a fulcrum, whereupon the upper portion 16A is inverted and detached
from the lower portion 16B as shown in (c) in FIG. 6. Specifically,
the upper portion 16A is reclosable while the upper portion 16A is
axially supported by the lower portion 16B. As shown in FIG. 7, the
upper portion 16A is held with the extruding plate 31 a on the
bottom side of the upper portion oriented upward, to thus assume a
position at which the cartridge 31 in the indentation 30a becomes
removable.
By reference to (a) to (e) in FIG. 8, (a) and (b) in FIG. 9, and
(a) and (b) in FIG. 10, the holding mechanism 40 for integrally
attaching or detaching the squeegee unit 16 to or from the joint 14
is now described. First, by reference to (a) to (e) in FIG. 8, a
shape of the joint 14 is described. In FIG. 8, (a) shows a shape of
the joint 14 shown in FIG. 3 when viewed in plane, and in FIG. 8,
(b), (c), (d) and (e) show a cross section A, a cross section B, a
cross section C, and a cross section D in (a) in FIG. 8. The joint
plate 14a is a plate member that comes to a position facing an
upper surface side of the squeegee unit 16 when the squeegee unit
16 remains joined to the joint 14. A downwardly-extended
protuberance 14c is provided along an edge on one side of the plate
member. A shaft holding member 43 that is axially supported by a
shaft support 44 having a vertically-oriented pivot 44a is disposed
in an extension of the longitudinal direction of the protuberance
14c of the joint plate 14a, so as to be turnable around the pivot
44a. The shaft member 45 having a rectangular cross section
horizontally protrudes from the shaft holding member 43 in a
direction parallel to the protuberance 14c.
As shown in (b) in FIG. 8, an inwardly-protruding protrusion 41 is
provided on the protuberance 14c when viewed in the cross section
A. The positioning hole 41a into which the positioning pin 38a (see
(a) and (b) in FIG. 5) is to be fitted is opened in the protrusion
41. As shown in (c) in FIG. 8, another inwardly-protruding
protrusion 42 is provided in the protuberance 14c when viewed in
the cross section B. A fitting groove 42a having a rectangular
cross section into which the shaft member 45 is to be fitted is
formed in the protrusion 42.
Further, when viewed in the cross section C shown in (d) in FIG. 8,
the protrusion is not provided in the protuberance 14c, and the
shaft member 45 is situated along a direction parallel to the
protuberance 14c. Further, as shown in (e) in FIG. 8, the pivot 44a
is fixed in the vertical direction on the joint plate 14a when
viewed in the cross section ID, and the shaft, holding member 43
having a built-in shaft bearing is rotatably attached to the pivot
44a. The shaft member 45 having a rectangular cross section
horizontally extends out of the shaft holding member 43, and the
shaft member 45 is turnable around the pivot 44a (see arrow "a"
shown in (a) in FIG. 8).
When the joint 14 is caused to hold the squeegee unit 16, the shaft
member 45 is first turned (as designated by arrow "b") around the
shaft support 44 as shown in (a) in FIG. 9, thereby positioning the
squeegee unit 16 such that the center line of the fitting slot 37a
opened in the hole 37 of the squeegee unit 16 comes into alignment
with an extension "c" of the shaft member 45. Next, as shown in (b)
in FIG. 9, the squeegee unit 16 is moved along the axial direction
of the shaft member 45 (as designated by arrow "d"), thereby
fitting the shaft member 45 into the fitting slot 37a. Further, the
shaft member 45 is pushed to a position where an extremity of the
shaft member 45 contacts an end face 38b of the positioning section
38.
Subsequently, as shown in (a) in FIG. 10, the squeegee unit 16 is
turned around the shaft support 44 (as designated by arrow "e") to
a position where the shaft member 45 comes into alignment with the
protuberance 14c. The shaft member 45 is fitted into and pressed
against the fitting groove 42a of the protrusion 42. The axis of
the positioning pin 38a comes into agreement with the positioning
hole 41a of the protrusion 41. Next, as shown in (b) in FIG. 10,
the squeegee unit 16 is shifted in a direction (designated by arrow
"f") in which the positioning pin 38a fits into the positioning
hole 41a, where an end of the positioning section 38 contacts the
protrusion 41. The shaft member 45 thereby fits into the fitting
slot 37a and further into the fitting groove 42a. As a result of
the positioning pin 38a fitting into the positioning hole 41a, the
squeegee unit 16 is positioned and held at a correct location by
the joint 14.
Specifically, the holding mechanism 40 that holds the squeegee unit
16 in alignment with the joint 14 is made up of the shaft support
44 that is coupled to the joint 14 and that has the
vertically-oriented pivot 44a, the shaft member 45 that
horizontally extends from the shaft support 44 and that is turnable
around the pivot 44a, and the fitting section 36 that is formed in
the squeegee unit 16 and that has the fitting slot 37a into which
the shaft member 45 is removably fitted.
A cross sectional profile of the fitting slot 37a is defined in
imitation of the rectangular cross section of the shaft member 45
and yields a turn inhibition effect. For this reason,
inconvenience, which would otherwise be caused by turning of the
squeegee unit 16 around the shaft member 45, is prevented.
Specifically, in the holding mechanism 40, the fitting slot 37a and
the shaft member 45 configure a turn inhibition mechanism that
inhibits occurrence of relative turning between the fitting section
36 and the shaft member 45 while the shaft member 45 remains fitted
to the fitting section 36.
Furthermore, the positioning pin 38a of the fitting section 36 is
fitted into the positioning hole 41a, and the positioning section
38 contacts the protrusion 41. Moreover, the shaft member 45 is
fitted into the fitting groove 42a, thereby preventing occurrence
of axial and radial positional misalignment among the fitting
section 36, the positioning pin 38a, and the shaft member 45.
Specifically, in the holding mechanism 40, a combination of the
fitting section 36 with the positioning pin 38a and a combination
of the shaft member 45 with the fitting groove 42a configure a
misalignment prevention mechanism that regulates relative, axial,
radial displacement between the fitting section 36 and the shaft
member 45 while the shaft member 45 remains fitted to the fitting
section 36.
In the configuration mentioned as the example of the joint 14 in
the embodiment, the joint block 14b is provided on the joint plate
14a, and the holding mechanism 40 that positions and holds the
squeegee unit 16 is additionally built into the protuberance 14c
downwardly extended from one edge of the joint plate 14a. However,
another example of the mechanism can also be adopted, so long as
the holding mechanism 40 that is joined to the head drive mechanism
13 and that positions and holds the squeegee unit 16 can be built
into the mechanism.
The squeegee unit 16 equipped with the cartridge 31 is thus held by
the joint 14, whereby the squeegee unit becomes able to perform
screen printing. During screen printing, the cream solder 9 in the
cartridge is pressurized by the pressurizing plate 32, whereupon
the print space 35 of the squeegee unit 16 is filled with the cream
solder 9 that has been reformed to assume appropriate viscosity as
mentioned above. The squeegee unit 16 is slid over the mask plate
7. The pattern holes 7a of the mask plate 7 are thereby filled with
the paste in the print space 35 by the print plane located between
the scraping members 18A, 18B.
The pattern holes 7a are sequentially filled with the cream solder
9 by further moving the squeegee unit 16. After all of the pattern
holes 7a are filled with the cream solder, the substrate
positioning section 2 is lowered, thereby releasing the mask plate.
Specifically, the cream solder 9 caught in the pattern holes 7a
descends with the substrate 5, to thus leave the pattern holes 7a.
Screen-printing the substrate 5 with the cream solder 9 is thereby
completed.
The cream solder 9 of the cartridge 31 is pressurized in the
squeegee head 10, thereby letting the print space 35 located
downward accommodate the cream solder 9. The cream solder 9 is
brought into contact with the surface of the mask plate 7, thereby
printing the substrate with the cream solder 9. When the cream
solder 9 of the cartridge 31 has run out in the middle of foregoing
operation, work of replacing the cartridge 31 is performed. During
the work of replacing the cartridge 31, working operation shown in
(a) and (b) in FIG. 9 and (a) and (b) in FIG. 10 are performed in
reverse order.
The shaft member 45 fitted to the fitting slot 37a of the squeegee
unit 16 is turned around the shaft support 44, thereby turning the
squeegee unit 16 within a horizontal plane with respect to the
joint 14. Next, the squeegee unit 16 is moved in the squeegeeing
direction, thereby detaching the fitting section 36 from the shaft
member 45. The squeegee unit 16 is thereby detached from the joint
14. While the squeegee unit 16 stays at a position where superior
workability is attained, the upper portion 16A and the lower
portion 16B of the squeegee unit 16 are opened, and the cartridge
31 is replaced.
As mentioned above, in relation to the screen printing of the
invention, the holding mechanism 40 is made up of the cartridge 31,
the print space 35, and the scraping members 18A, 18B and positions
and holds the squeegee unit 16, which can be integrally attached to
and detached from the joint 14, with respect to the joint 14. The
holding mechanism 40 is built from the shaft support 44 that is
coupled to the joint 14 and that has the vertically-oriented pivot
44a, the shaft member 45 that horizontally extends from the shaft
support 44 and is turnable around the pivot 44a, and the fitting
section 36 that is formed in the squeegee unit 16 and to which the
shaft member 45 is removably fitted. The entirety of the squeegee
unit 16 can be removably attached by only moving the squeegee unit
16 in the horizontal direction. Thus, the configuration of the
screen printer is miniaturized, and cartridge replacement work can
be easily performed.
The embodiment provides an example intended for the configuration
where the squeegee unit 16 can be split into the upper portion 16A
and the lower portion 16B. However, the invention is not always
limited to the embodiment. Even the configuration in which portions
equivalent to the upper portion 16A and the lower portion 16B are
fixedly integrated into a single piece is an object of application
of the invention.
The patent application is based on Japanese Patent Application
(JP-2011-245145) filed on Nov. 9, 2011, the subject matter of which
is incorporated herein by reference in its entirety.
INDUSTRIAL APPLICABILITY
The screen printer and the screen printing method of the invention
yield an advantage of the ability to miniaturize a configuration of
the printer and facilitate cartridge replacement work and are also
applied to a field in which a substrate is printed with electronic
component bonding paste.
DESCRIPTIONS OF THE REFERENCE NUMERALS AND SYMBOLS
1 SCREEN PRINTER
2 SUBSTRATE POSITIONING SECTION
5 SUBSTRATE
7 MASK PLATE
7a PATTERN HOLE
9 CREAM SOLDER
10 SQUEEGEE HEAD
11 HEAD ELEVATION MECHANISM
12 HEAD MOVING MECHANISM
13 HEAD DRIVE MECHANISM
14 JOINT
15 CYLINDER
16 SQUEEGEE UNIT
16A UPPER PORTION
16B LOWER PORTION
17 HINGE
18A, 18B SCRAPING MEMBER
31 CARTRIDGE
32 PRESSURIZING PLATE
35 PRINT SPACE
36 FITTING SECTION
37a FITTING SLOT
38a POSITIONING PIN
40 HOLDING MECHANISM
41a POSITIONING HOLE
42a FITTING GROOVE
43 SHAFT HOLDING MEMBER
44 SHAFT SUPPORT
44a PIVOT
45 SHAFT MEMBER
* * * * *